/**
 *
 * htmlParser改造自: https://github.com/blowsie/Pure-JavaScript-HTML5-Parser
 *
 * author: Di (微信小程序开发工程师)
 * organization: WeAppDev(微信小程序开发论坛)(http://weappdev.com)
 *               垂直微信小程序开发交流社区
 *
 * github地址: https://github.com/icindy/wxParse
 *
 * for: 微信小程序富文本解析
 * detail : http://weappdev.com/t/wxparse-alpha0-1-html-markdown/184
 */
// Regular Expressions for parsing tags and attributes
var startTag = /^<([-A-Za-z0-9_]+)((?:\s+[a-zA-Z_:][-a-zA-Z0-9_:.]*(?:\s*=\s*(?:(?:"[^"]*")|(?:'[^']*')|[^>\s]+))?)*)\s*(\/?)>/,
    endTag = /^<\/([-A-Za-z0-9_]+)[^>]*>/,
    attr = /([a-zA-Z_:][-a-zA-Z0-9_:.]*)(?:\s*=\s*(?:(?:"((?:\\.|[^"])*)")|(?:'((?:\\.|[^'])*)')|([^>\s]+)))?/g; // Empty Elements - HTML 5

var empty = makeMap('area,base,basefont,br,col,frame,hr,img,input,link,meta,param,embed,command,keygen,source,track,wbr'); // Block Elements - HTML 5

var block = makeMap(
    'a,address,code,article,applet,aside,audio,blockquote,button,canvas,center,dd,del,dir,div,dl,dt,fieldset,figcaption,figure,footer,form,frameset,h1,h2,h3,h4,h5,h6,header,hgroup,hr,iframe,ins,isindex,li,map,menu,noframes,noscript,object,ol,output,p,pre,section,script,table,tbody,td,tfoot,th,thead,tr,ul,video'
); // Inline Elements - HTML 5

var inline = makeMap(
    'abbr,acronym,applet,b,basefont,bdo,big,br,button,cite,del,dfn,em,font,i,iframe,img,input,ins,kbd,label,map,object,q,s,samp,script,select,small,span,strike,strong,sub,sup,textarea,tt,u,var'
); // Elements that you can, intentionally, leave open
// (and which close themselves)

var closeSelf = makeMap('colgroup,dd,dt,li,options,p,td,tfoot,th,thead,tr'); // Attributes that have their values filled in disabled="disabled"

var fillAttrs = makeMap('checked,compact,declare,defer,disabled,ismap,multiple,nohref,noresize,noshade,nowrap,readonly,selected'); // Special Elements (can contain anything)

var special = makeMap('wxxxcode-style,script,style,view,scroll-view,block');

function HTMLParser(html, handler) {
    var index,
        chars,
        match,
        stack = [],
        last = html;

    stack.last = function () {
        return this[this.length - 1];
    };

    while (html) {
        chars = true; // Make sure we're not in a script or style element

        if (!stack.last() || !special[stack.last()]) {
            // Comment
            if (html.indexOf('<!--') == 0) {
                index = html.indexOf('-->');

                if (index >= 0) {
                    if (handler.comment) handler.comment(html.substring(4, index));
                    html = html.substring(index + 3);
                    chars = false;
                } // end tag
            } else if (html.indexOf('</') == 0) {
                match = html.match(endTag);

                if (match) {
                    html = html.substring(match[0].length);
                    match[0].replace(endTag, parseEndTag);
                    chars = false;
                } // start tag
            } else if (html.indexOf('<') == 0) {
                match = html.match(startTag);

                if (match) {
                    html = html.substring(match[0].length);
                    match[0].replace(startTag, parseStartTag);
                    chars = false;
                }
            }

            if (chars) {
                index = html.indexOf('<');
                var text = '';

                while (index === 0) {
                    text += '<';
                    html = html.substring(1);
                    index = html.indexOf('<');
                }

                text += index < 0 ? html : html.substring(0, index);
                html = index < 0 ? '' : html.substring(index);
                if (handler.chars) handler.chars(text);
            }
        } else {
            html = html.replace(new RegExp('([\\s\\S]*?)</' + stack.last() + '[^>]*>'), function (all, text) {
                text = text.replace(/<!--([\s\S]*?)-->|<!\[CDATA\[([\s\S]*?)]]>/g, '$1$2');
                if (handler.chars) handler.chars(text);
                return '';
            });
            parseEndTag('', stack.last());
        }

        if (html == last) throw 'Parse Error: ' + html;
        last = html;
    } // Clean up any remaining tags

    parseEndTag();

    function parseStartTag(tag, tagName, rest, unary) {
        tagName = tagName.toLowerCase();

        if (block[tagName]) {
            while (stack.last() && inline[stack.last()]) {
                parseEndTag('', stack.last());
            }
        }

        if (closeSelf[tagName] && stack.last() == tagName) {
            parseEndTag('', tagName);
        }

        unary = empty[tagName] || !!unary;
        if (!unary) stack.push(tagName);

        if (handler.start) {
            var attrs = [];
            rest.replace(attr, function (match, name) {
                var value = arguments[2] ? arguments[2] : arguments[3] ? arguments[3] : arguments[4] ? arguments[4] : fillAttrs[name] ? name : '';
                attrs.push({
                    name: name,
                    value: value,
                    escaped: value.replace(/(^|[^\\])"/g, '$1\\"') //"
                });
            });

            if (handler.start) {
                handler.start(tagName, attrs, unary);
            }
        }
    }

    function parseEndTag(tag, tagName) {
        // If no tag name is provided, clean shop
        if (!tagName) var pos = 0;
        // Find the closest opened tag of the same type
        else {
            tagName = tagName.toLowerCase();

            for (var pos = stack.length - 1; pos >= 0; pos--) if (stack[pos] == tagName) break;
        }

        if (pos >= 0) {
            // Close all the open elements, up the stack
            for (var i = stack.length - 1; i >= pos; i--) if (handler.end) handler.end(stack[i]); // Remove the open elements from the stack

            stack.length = pos;
        }
    }
}

function makeMap(str) {
    var obj = {},
        items = str.split(',');

    for (var i = 0; i < items.length; i++) obj[items[i]] = true;

    return obj;
}

module.exports = HTMLParser;
